[Qemu-devel] [PATCH for-2.7 06/15] gluster: Implement .bdrv_lockf

[Fam Zheng <famz@redhat.com>]

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/gluster.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/block/gluster.c b/block/gluster.c
index 51e154c..e76ec87 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -672,6 +672,36 @@ static void qemu_gluster_close(BlockDriverState *bs)
     glfs_fini(s->glfs);
 }
 
+static int qemu_gluster_lockf(BlockDriverState *bs, BdrvLockfCmd cmd,
+                              Error **errp)
+{
+    BDRVGlusterState *s = bs->opaque;
+    int ret;
+    struct flock fl = (struct flock) {
+        .l_start = 0,
+        .l_whence  = SEEK_SET,
+        .l_len = 0,
+    };
+    switch (cmd) {
+    case BDRV_LOCKF_RWLOCK:
+        fl.l_type = F_WRLCK;
+        break;
+    case BDRV_LOCKF_ROLOCK:
+        fl.l_type = F_RDLCK;
+        break;
+    case BDRV_LOCKF_UNLOCK:
+        fl.l_type = F_UNLCK;
+        break;
+    default:
+        abort();
+    }
+    ret = glfs_posix_lock(s->fd, F_SETLK, &fl);
+    if (ret == -1) {
+        error_setg_errno(errp, errno, "Failed to lock image");
+    }
+    return ret == -1 ? -errno : 0;
+}
+
 static int qemu_gluster_has_zero_init(BlockDriverState *bs)
 {
     /* GlusterFS volume could be backed by a block device */
@@ -713,6 +743,7 @@ static BlockDriver bdrv_gluster = {
     .bdrv_co_readv                = qemu_gluster_co_readv,
     .bdrv_co_writev               = qemu_gluster_co_writev,
     .bdrv_co_flush_to_disk        = qemu_gluster_co_flush_to_disk,
+    .bdrv_lockf                   = qemu_gluster_lockf,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 #ifdef CONFIG_GLUSTERFS_DISCARD
     .bdrv_co_discard              = qemu_gluster_co_discard,
@@ -740,6 +771,7 @@ static BlockDriver bdrv_gluster_tcp = {
     .bdrv_co_readv                = qemu_gluster_co_readv,
     .bdrv_co_writev               = qemu_gluster_co_writev,
     .bdrv_co_flush_to_disk        = qemu_gluster_co_flush_to_disk,
+    .bdrv_lockf                   = qemu_gluster_lockf,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 #ifdef CONFIG_GLUSTERFS_DISCARD
     .bdrv_co_discard              = qemu_gluster_co_discard,
@@ -767,6 +799,7 @@ static BlockDriver bdrv_gluster_unix = {
     .bdrv_co_readv                = qemu_gluster_co_readv,
     .bdrv_co_writev               = qemu_gluster_co_writev,
     .bdrv_co_flush_to_disk        = qemu_gluster_co_flush_to_disk,
+    .bdrv_lockf                   = qemu_gluster_lockf,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 #ifdef CONFIG_GLUSTERFS_DISCARD
     .bdrv_co_discard              = qemu_gluster_co_discard,
@@ -794,6 +827,7 @@ static BlockDriver bdrv_gluster_rdma = {
     .bdrv_co_readv                = qemu_gluster_co_readv,
     .bdrv_co_writev               = qemu_gluster_co_writev,
     .bdrv_co_flush_to_disk        = qemu_gluster_co_flush_to_disk,
+    .bdrv_lockf                   = qemu_gluster_lockf,
     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 #ifdef CONFIG_GLUSTERFS_DISCARD
     .bdrv_co_discard              = qemu_gluster_co_discard,
-- 
2.8.0